The invention relates to cartridge magazines for automatic firearms, and to cartridge followers for so-called box magazines, in which the cartridges are arranged side-by-side in one or more columns for movement laterally of themselves toward the open end of the magazine from which each round is fed into the cartridge chamber by the slide or bolt member.
In conventional magazines of this type, such as those used in the United States Government Model 1911 .45 caliber automatic pistol, commonly referred to as the Colt .45, a single column of cartridges is disposed within an elongated tube that is closed at the lower end. The cartridges are urged upward by a spring which is compressed between the bottom of the magazine and a follower which engages the lower-most cartridge in the column. In most cases, the follower is a rigid, usually sheet-metal member, having a cartridge-engaging portion that is disposed transversely of the magazine tube but longitudinally of the cartridges. A positioning and guide portion at its rear extends downward along the wall of the magazine tube. In the follower of the Government Model 1911, the forward end of the cartridge-engaging portion also has a depressed step or tab for actuating the slidestop of the pistol when the last round is fired, so that the slide is automatically held open when the magazine is empty. Due to space limitations imposed by the length and width of the pistol grip, or of the receiver in an automatic rifle or shotgun, magazines for these guns have heretofore been designed to hold a specified maximum number of rounds. In the case of the Goverment Model 1911 types, prior magazines have been capable of holding only seven rounds.
The object of the present invention is to increase the capacity of cartridge magazines of this type without changing the outside dimensions of the magazine tube, so that it is usable in existing weapons without any modification of the gun.